• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.7
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• pp.434-441
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• 1988

This paper proposes a new invention of the integrated generator converter system for the HVDC transmission. And it analyses the general formula for eddy currents in the rotor iron using the double Fourier series in order to trace the smallest eddy current losses of the system which connects a new designed synchronous generator windings or conventional synchronous generator windings with the v Graetz bridges.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.131-132
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• 2012

Implementation of fuzzy controller for the rotor side converter of a utility-connected double-fed induction generator (DFIG) for wind power generation systems (WPGS) described in this paper. In the control schemes, real and reactive powers (PQ) at the stator side of DFIG are strictly controlled to supply the power to the grid. A TMS320VC33 DSP is selected as the controller of this system.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.986-989
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• 1999

An 12bit current-mode folding and interpolation analog to digital converter (ADC) with multiplied folding amplifiers is proposed in this paper. A current - mode multiplied folding amplifier is employed not only to reduced the number of reference current source, but also to decrease a power dissipation within the ADC. The designed ADC fabricated by a 0.6${\mu}{\textrm}{m}$ n-well CMOS double metal/single poly process. The simulation result shows the power dissipation of 280㎽ with a power supply of 5V.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.3
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• pp.188-198
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• 2010

Recently, as the demand of the environmental-friendly energy storage system such as an electric double-layer condenser increases, that of the bidirectional charger/discharger for the systems also increases. However, when charging/discharging mode-change occurs, the charger/discharger employing a bi-directional DC-DC converter with a commercialized analog controller has a complex circuit scheme, and a poor transient response. On the other hand, if a single digital controller is used for the bi-directional mode, the system performances can be improved by application of an advanced power-processing algorithm. In the paper, an environmental-friendly power storage systems including an Electric Double Layer Capacitor(EDLC) banks were developed with a bi-directional buck-boost converter and a digital signal processor (TMS320F28335). A simulation test-bed was realized and tested by MATLAB Simulink, and the hardware experiment was performed which shows that the dynamic response was improved such as the simulation results.

• Journal of IKEEE
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• v.22 no.4
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• pp.1218-1221
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• 2018

This paper presents a low-power 0.6-V 10-bit 200-kS/s double rail-to-rail successive approximation register (SAR) analog-to-digital converter (ADC). The proposed scheme allows input signal with 4 times power which is compared with conventional one by applying proposed rail-to-rail scheme, and that improves signal-to-noise ratio(SNR) of NTV SAR ADCs. The prototype was designed using 65-nm CMOS technology. At a 0.6-V supply and $2.4-V_{pp}$ (differential) and 200-kS/s, the ADC achieves an SNDR of 59.87 dB and consumes 364.5-nW. The ADC core occupies an active area of only $84{\times}100{\mu}m^2$.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.187-194
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• 1999

In the design of catalytic converter, velocity distribution is more important than pressure drop because monolith pressure drop is about 80% of overall pressure drop. For the catalytic converter with single diffuser, pressure drop is decreased as the angle of diffuser decrease, but when the angle is below 18$^{\circ}$, the effect is almost negligible . For the catalytic converter with double diffuser, variation of the angle of the first diffuser shows the same trend as the pressure drop while the shape of diffuser gives little influence on that The outlet shape gives negligible effect on the pressure drop and velocity . distribution . Results show that recirculation region of commercial model is aoubt 30% of the total area in the front of monolith. For the catalytic converter with Model 11 that was presented in the study, recirculation region was not detected more uniform velocity distribution was obtained, and pressure drop was also decreased.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.1
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• pp.19-29
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• 2003

This paper proposes a CMOS readout circuit for uncooled micro-bolometer arrays adopting a four-point step calibration technique. The proposed readout circuit employing an 11b analog-to-digital converter (ADC), a 7b digital-to-analog converter (DAC), and an automatic gain control circuit (AGC) extracts minute infrared (IR) signals from the large output signals of uncooled micro-bolometer arrays including DC bias currents, inter-pixel process variations, and self-heating effects. Die area and Power consumption of the ADC are minimized with merged-capacitor switching (MCS) technique adopted. The current mirror with high linearity is proposed at the output stage of the DAC to calibrate inter-pixel process variations and self-heating effects. The prototype is fabricated on a double-poly double-metal 1.2 um CMOS process and the measured power consumption is 110 ㎽ from a 4.5 V supply. The measured differential nonlinearity (DNL) and integrat nonlinearity (INL) of the 11b ADC show $\pm$0.9 LSB and $\pm$1.8 LSB, while the DNL and INL of the 7b DAC show $\pm$0.1 LSB and $\pm$0.1 LSB.

• Journal of the Korean Magnetics Society
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• v.11 no.5
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• pp.222-225
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• 2001

The planar type inductors have a good potential for the application of miniaturized low power DC-DC converters. For those high quality application, the reduction of coil loss and also magnetic films which have good high frequency properties are required. Fabricated inductor was consisted of FeTaN/Ti magnetic film and electroplated Cu coil thickness of 100$\mu\textrm{m}$ and $SiO_2$ as a insulating layer. The inductor was designed double rectangular spiral shape for magnetic field highly confining within the device. The measured value of inductance and resistance were 980 nH and 1.7 $\Omega$ at 1 MHz as operating frequency of device. The Q factor is 3.55 at 1 MHz.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.1
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• pp.21-26
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• 2001

This paper proposes a new double-connected 3-phase voltage source inverter with improved output voltage waveform. An auxiliary single-phase inverter injects a ripple voltage into the double-connected inverter to converter 12-step operation to 36-step operation. The KVA rating of the output phase-shifting transformer is reduced by employing a harmonic canceling reactor. The whole rectifier-inverter system including the proposed technique is introduced, and the experimental results are provided.

• ETRI Journal
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• v.25 no.4
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• pp.270-273
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• 2003

This paper presents a simple process to integrate thin-film inductors with a bottom NiFe magnetic core. NiFe thin films with a thickness of 2 to 3${\mu}m$ were deposited by sputtering. A polyimide buffer layer and shadow mask were used to relax the stress of the NiFe films. The fabricated double spiral thin-film inductor showed an inductance of 0.49${\mu}H$ and a Q factor of 4.8 at 8 MHz. The DC-DC converter with the monolithically integrated thin-film inductor showed comparable performances to those with sandwiched magnetic layers. We simplified the integration process by eliminating the planarization process for the top magnetic core. The efficiency of the DC-DC converter with the monolithic thin-film inductor was 72% when the input voltage and output voltage were 3.5 V and 6 V, respectively, at an operating frequency of 8 MHz.